Photosynthesis provides _____ in the atmosphere that support(s) much of the life on earth.

Photosynthesis provides oxygen (O₂) in the atmosphere that supports much of the life on Earth. During the process of photosynthesis, plants, algae, and some bacteria convert carbon dioxide (CO₂) and water (H₂O) into glucose (C₆H₁₂O₆) and oxygen, using sunlight as energy. The general equation for photosynthesis can be expressed as:

$6 \, \text{CO}_2 + 6 \, \text{H}_2\text{O} \xrightarrow{\text{light}} \text{C}_6\text{H}_{12}\text{O}_6 + 6 \, \text{O}_2$

This produced oxygen is crucial for the survival of aerobic organisms, including humans, as it is used in cellular respiration to generate energy. Without photosynthesis, the levels of oxygen in the atmosphere would deplete over time, drastically affecting life's ability to thrive on our planet.